1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to an LCD device having less power consumption and a gate sharing structure and a method of driving the same.
2. Discussion of the Related Art
The LCD device as a display device is driven by using optical anisotropy and polarization properties of liquid crystal molecules. The LCD device is widely used for a display part of mobile electronic equipments, a monitor of computers and televisions.
The liquid crystal molecules have a definite alignment direction as a result of their thin and long shapes. The alignment direction of the liquid crystal molecules can be controlled by application of an electric field across the liquid crystal molecules. As the intensity or direction of the electric field is changed, the alignment of the liquid crystal molecules also changes.
The LCD device includes two substrates respectively including an electric field generating electrode and a liquid crystal layer therebetween. The alignment of the liquid crystal molecules are changed by an electric field between the electrodes such that images can be displayed by controlling light transmissivity.
The LCD device includes an array substrate, a color filter substrate and a liquid crystal layer interposed therebetween. The array substrate may include a pixel electrode and TFT, and the color filter substrate may include a color filter layer and a common electrode. The LCD device is driven by an electric field between the pixel electrode and the common electrode resulting in excellent properties of transmittance and aperture ratio. However, since this LCD device uses a vertical electric field, the LCD device has a bad viewing angle.
An in-plane switching (IPS) mode LCD device may be used to resolve the above-mentioned limitations. The related art IPS mode LCD device includes a color filter substrate, an array substrate facing the color filter substrate, and a liquid crystal layer interposed therebetween. Both common and pixel electrodes for driving the liquid crystal layer are formed on the array substrate such that a horizontal electric field is induced between the pixel and common electrodes. Since the liquid crystal molecules are driven by the horizontal electric field, the IPS mode LCD device has improved viewing angle. However, the IPS mode LCD device has disadvantages in the aperture ratio and the transmittance.
To overcome the disadvantages of the IPS mode LCD device, a fringe field switching (FFS) mode LCD device is introduced. Hereinafter, the related art FFS mode LCD device is explained.
FIG. 1 is a schematic view of the related art FFS mode LCD device, and FIG. 2 is a circuit diagram of pixels in the related art FFS mode LCD device.
Referring to FIGS. 1 and 2, in the related art FFS mode LCD device, a plurality of data lines DL1 to DL10 and a plurality of gate lines GL1 to GL4 are formed to cross each other. A plurality of pixels R11 to R43, G11 to G43 and B11 to B43 are defined by the plurality of data lines DL1 to DL10 and the plurality of gate lines GL1 to GL4.
Each of the plurality of pixels R11 to R43, G11 to G43 and B11 to B43 includes a thin film transistor (TFT) Tr, a storage capacitor Cst and a liquid crystal capacitor CLC. The liquid crystal capacitor CLC includes a pixel electrode (not shown) and a common electrode Vcom. The pixel electrode is electrically connected to the TFT.
The plurality of pixels R11 to R43, G11 to G43 and B11 to B43 are arranged in a stripe shape.
For example, the pixels arranged along a vertical direction include the same color filter, e.g., red color filter, and different color filters, e.g., red, green and blue color filters, are alternately arranged in the pixels along a horizontal direction.
In this pixel structure, the TFT in one pixel of vertically adjacent two pixels is electrically connected to the gate line between the vertically adjacent two pixels. Accordingly, an area for the TFT is required in each of the pixels R11 to R43, G11 to G43 and B11 to B43. As a result, the aperture ratio and the transmittance of the pixels are decreased by the region for the TFT.
Namely, although the FFS mode LCD device has been developed to overcome the disadvantages, e.g., the aperture ratio and the transmittance, of the IPS mode LCD device, there still are disadvantages in the aperture ratio and the transmittance.